DSNC - CICS Db2 transaction

Use DSNC to enter Db2® commands and carry out a range of other CICS® Db2 operations.

The DSNC transaction supports the following operations:
Note: The DSNC commands can be issued only from a CICS terminal.

The DSNC transaction executes program DFHD2CM1, which handles both CICS Db2 attachment facility and Db2 commands. You can distinguish Db2 commands from CICS Db2 attachment facility commands by the hyphen (-) character, which is entered with Db2 commands. This character is not a Db2 subsystem recognition character, but a command recognition character. It is always a -, independent of the character defining the Db2 subsystem, since CICS can only connect to one Db2 subsystem at a time. There is no need to use different Db2 subsystem recognition characters from CICS, and thus we use only the default - character.

Command routing and processing

When the connection between CICS and Db2 has been established, terminal users authorized by CICS can use the DSNC transaction to route commands to the Db2 subsystem for processing. Db2 checks that the user is authorized to issue the command entered. Responses are routed back to the originating CICS user. The command recognition character (CRC) of “-” must be used to distinguish Db2 commands from CICS Db2 attachment facility commands. This command recognition character is not used to identify the Db2 subsystem to which the command is to be sent. The command is sent to the Db2 subsystem to which CICS is currently connected. Figure 1 shows the CICS Db2 attachment facility commands. These require CICS authorization to use the DSNC transaction and the Db2 commands.
Figure 1. Examples of CICS Db2 attachment facility commands and some Db2 commands
The DSNC transaction can be used to issue CICS Db2 attachment facility commands and Db2 commands. CICS Db2 attachment facility commands, such as DSNC STRT, DSNC STOP, DSNC DISP and DSNC MODI, operate in the CICS address space. Db2 commands from DSNC, such as DSNC -DIS THREAD(*), are distinguished by a CRC of “-”, and they operate in the Db2 address space. Some other Db2 commands you can issue using DSNC are -REC, -STA, -STO and -TER.

Alternative transaction definitions supplied in sample group DFH$DB2

Alternative transaction definitions for CICS Db2 attachment facility commands are supplied with the following names:
  • DISC
  • DISP
  • STRT
  • STOP
  • MODI

The sample CICS Db2 group, DFH$DB2® contains the following transaction definitions for issuing Db2 commands. If they are installed, you can omit DSNC from the Db2 command.